James w



(No Mode 1.)

J. W. PACKARD.

VACUUM PUMP.

No. 406,110. Patented July 2,1889.

ATTORNEYS, I

' INVBNTOR:

BY Jaw UNITED STATES PATENT OEEIGE.

JAMES \V. PACKARD, OF BROOKLYN, NEWV YORK, ASSIGNOR OF ONE-HALF TONORMAN HUBBARD, OF SAME PLACE.

VACUUM-PUMP.

SPECIFICATION forming part of Letters Patent No. 406,110, dated July 2,1889.

Application filed September 28,1887. Serial No. 250,902- (No model.)

To all whom it 111 01; concern.-

Be it known that 1, JAMES W. PACKARD, of Brooklyn,in the county of Kingsand State of New York, have invented a new and Improved Vacuum-Pump, ofwhich the following is a full, clear, and exact description.

The invention consists of the construction, arrangement, and combinationof parts, all as hereinafter described and claimed.

Reference is to be had to the accompanying drawing, forming a part ofthis specification, in which the figure is a longitudinal sectionalelevation of a pump made in accordance with my invention.

The piston-rod A is made hollow for a portion of its length and thepassage a therein is made in two diameters, the same being somewhatenlarged at aj, at and near the innor end of the piston-rod.

In the passage a is fitted the small rod B, which operates the valve 0at the induction end of the pump. The rod B is connected to the valve 0by a ball-and-socket joint, and is split at its upper end to formspring-tongues, which act as friction-surfaces in the passage a, so thatthe rod will be raised by the lifting of the piston until the ends ofthe springs reach the enlargement to, when the rod will be released andpermit the valve '0 to close of its own weight. The seat for the valve 0is formed in the T-coupling D, and it is held to a very limited movementby the pin d, passed through a slot (1', formed in the extension (1 atthe bottom of the valve.

The branch D of the coupling D serves to connect the pump with thevessel to be exhausted. The lower branch D projects be low the branch D,and is closed with a screwcap B and constitutes a trap to catch anymoisture that may condense in the pump, and which may be removed byremoving the cap D The upper end of the valve 0 is formed with a smallprojection c, which is screwthreaded upon its outer surface and formedwith a cup or socket c at the top to receive the ball I) of the rod B.This ball is held in the cup or socket c by the cap-plate f, placed uponthe rod and screwed upon projection 0, thus forming a very cheap andvery practical ball-and-socket connection of the rod 13 with the valve(1, which obviates all binding of the rod and gives the valve 0 perfectfreedom of action.

The great advantage of the construction involving a universal jointbetween the valve and the valve-stem, as shown in my ball-andsocketjoint, is that the valve is left free to seat itself perfectly,unaffected by any buck} ling or warping of the valve-stem. More over,should the valve-stem be broken in the rapid operation of the pump itcan be removed and'replaced at slight cost and without the necessity ofputting in a new valve, which would have to be ground to a seat in theusual tedious and costly manner.

In the piston-head E is fitted the valve I which projects below thepiston-head, and is lifted when it nears the limit of the pistonstrokeby con tact of the valve with the lower cylinder-head G.

In the upper cylinder=head H is formed an opening h, through whichprojects the ex haust-check valve J, so that the said valve will beopened by the piston-head striking the lower end of the valve. Thisvalve is shown open in the drawings. As the piston head startsdownward,the valve will close of its own weight and prevent theadmission of air to the pump-cylinder. The valve J is held in a separatecasing K, formed with a flange 6, through which are passed thefastening-screws e for securing the casing and inclosed valve to thehead-plate II in position over the aperture h in the. said head-plate.The bottom of the casing K is formed with the valve-seat h, whichcoincides with the aperture h, as shown clearly in the drawings. The topof the easing K is closed by a screw-plug k, which is formed with acentral cavity is to receive and guide the stemj of the valve J, so thatall lateral movement or displacement of the valve is obviated.

The great advantage and necessity of having the valve in the pistonpositively operated in order that a high vacuum maybe produced dependson the fact that this valve is to be opened at the moment when therapidly=reciprocating piston is reversing its motion. Consequently themomentum of the valve (a by no means insignificant force) tends to keepit closed and the tension of the small claim as new, and desire tosecure by Letters Patent, is-

1. In a mechanical air pump, the combination of the cylinder, thepiston, the valve in the piston, and the projecting valve-stem,

which strikes the cylinder-head as the piston approaches one extremityof its travel, substantially as described.

2. In a mechanical air-pump, the combination of the cylinder, thepiston, the positivelyoperated induction-valve at one end of thecylinder, the valve in the piston, together with its projectingvalve-stem, which strikes the cylinder-head, and the eduction-valve atthe other end of the cylinder, together with its projecting valve-stem,which is struck by the piston, substantially as described.

3. In a mechanical air-pump, the combination of the cylinder, the pistonwith its hollow piston-rod bored to different diameters at dif ferentpoints in its length, the valve in the cylinder-head, the valve-stein,which extends into the hollow piston-rod and has frictional contacttherewith, and the universal jointbetween said valve-stem and valve,whereby said valve is positively operated in both directions,substantially as described.

t. In a mechanical air-pump, the combination of the cylinder, the pistonwith its hollow piston-rod, the valve in the cylinder-head, thevalve-stem, which extends into the hollow piston-rod and has frictionalcontact therewith by means of the split and expanded end of saidvalve-stem, and the universal joint between said VitlVOS'EGiH and valve,substantially described.

JAMES W. PACKARD.

\Vitnesses:

ED. BEESLEY, .TAMEs E. PEARCE.

